So you think you can test ….

Recently I saw this tweet: “a lot of testers don’t consider alternatives because they don’t know them”. It was a reaction in a discussion about a Dutch article with the title „The days of the ‘Dutch school of testing’ are over”. Jan Jaap claims that Dutch testers suffer from “Law of the handicap of a head start“. Really? I don’t think it is the handicap of a head start. Did we (Dutch testers) ever had a head start? I think it is something that is called “The Dunning-Kruger effect“.

Dunning KrugerThe Dunning-Kruger effect, named after David Dunning and Justin Kruger of Cornell University, occurs when incompetent people not only perform a task poorly or incompetently, but lack the competence to realize their own incompetence at a task and thus consider themselves much more competent than everyone else. Put more crudely, they’re too stupid to realize they’re stupid. The inverse also applies: competent people tend to underestimate their ability compared to others. (Source: Rational Wiki)

In the words of Dunning and Kruger: this overestimation occurs, in part, because people who are unskilled in these domains suffer a dual burden: Not only do these people reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the metacognitive ability to realize it.

I think many testers don’t realize that they actually know very little about testing at all. And that is why they don’t do anything to get better. They are also not encouraged much by their colleagues. Testing is often underestimated. I guess everyone has examples of managers who do not value testing as much as we would want them to. Testing is often devalued as “pushing buttons” and “everybody can test” is believed by many. I have seen companies who use testing as education, a first step in an IT career…

But there is more… I have worked as a selling and hiring manager and I experienced that there is a lack of competence in spotting talented testers. If you have the right certificates, people believe that you are a good tester. Because they simply do not know how to spot an excellent tester. In my recent job search nobody asked me to SHOW them my testing skills. We only talked about it.



  1. Hi Huib,
    I understand your point here, this Dunning-Kruger effect is definitely interesting. But suggesting all Dutch testers are too incompetent to see their own incompetence goes beyond my boundaries. I even think you unjust brutalize a lot of testers with it, I think a lot of testers are quite good in (only) one form of testing. The problem is most Dutch testers limit themselves to this one form. I think they don’t know there are other forms of testing out there. And they don’t understand the underlying assumptions of the form of testing they use. Is that incompetency? Maybe you could say that, I would rather call it a limited view on testing. And I think I am allowed to say so because until three years I had this limited view as well.
    I think we mostly agree, I draw less far-reaching conclusions. I think we can also agree that a lot of Dutch testers should broaden their view, study other forms/ways of testing and should start experimenting with these other forms of testing. And you know what? From my own experience I can tell everybody it not only makes you a better tester but it makes testing itself also more fun!
    Jan Jaap

    • Is that incompetency? Maybe you could say that, I would rather call it a limited view on testing”

      Isn’t that the same? Competence = “the ability to do something successfully or efficiently” (see Oxford Dictionary).

      To be able to do testing successfully or efficiently you need to adapt your testing to the context. By limiting yourself to one form of testing, it guess in many situations the testing they do is unsuccessful and inefficient. And management is unable to see that unfortunately.

  2. Personally, I found the best antidote to the D/K effect was engagement with other testers outside of my own organisation. Conferring with others at meetups/conferences/forums etc has given me far more exposure to the range variety within the testing field than any course, certification or book could ever do.

    We also had a similar article on TTP recently:

  3. Very good point Huib.
    I guess the next logical question is ‘what do we do about it?’ Convincing people who do not know that they need convincing, that they are worse at something than they thought they were, is not an easy task at all. I’d be very interested to discuss approaches that can be taken, and how managers in particular can be coached in order to help those who are suffering from the Dunning and Kruger effect to improve without destroying motivation completely.

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